Kankou (a.k.a. Umibouzu, 星海坊主) is Kagura and Kamui's father and one of the last members of the Yato clan. Like Kagura, he fights using an umbrella, but is also shown to be strong in his own right. He is one of the few characters able to overpower Kagura. He appears when an alien appears and takes over the Terminal, helping the Yorozuya defeat the creature. It's revealed that he has a cybernetic arm.

After he leaves to travel the galaxy hunting aliens, he's next heard from in the form of a letter. He tells Kagura that Sadaharu is also a monster they should get rid of. He becomes the leader of the "Principality" in the anime, recruited by a Char Aznable doppelganger. In the manga, he's recruited by a Darth Vader lookalike.

Later in the manga and anime series. He also participated in a hair growing shampoo advertisement which the Yorozuya complained that the advertisement is too long.

Hideaki Sorachi revealed in a Q&A in volume 57 that Umibozu's real name is Kankou.